Hi. Unfortunately, we were unable to reproduce this issue with ordinary archive, everything works fine. If it is possible, please open a ticket in our helpdesk system and provide us your file to reproduce this issue. Otherwise please ask your client about the software he used to produce the archive. Also a good idea is to ask him to create archive with dummy folders/files with dots and see if error persists.

Forums are limited to image files (as attachments were designed to add images), right.

Version 8.0 is probably not the best thing to use in regards to ZIP: even version 8 had 8.2 as the last build, and you also have a license with version 9. So it makes sense to upgrade and see if the issue is still present. If there was a bug which has been fixed later, fixing it in the old version is not possible anyway.

It is utility from Info ZIP, which shows advanced information about zip archive.
It is available on *nix platforms or can be downloaded separately for Windows (also, as far as I remember unzip should have command-line key to work like zipinfo).